Convert //chrome/browser/chromeos from scoped_ptr to std::unique_ptr

chrome/browser/chromeos/preferences_chromeos_browsertest.cc

Index: chrome/browser/chromeos/preferences_chromeos_browsertest.cc
diff --git a/chrome/browser/chromeos/preferences_chromeos_browsertest.cc b/chrome/browser/chromeos/preferences_chromeos_browsertest.cc
index a03fcc58359c123386adc4c1eb89b7851fc5bed6..16d0d07b3eb25d7dfbd3582f96e13c469136460e 100644
--- a/chrome/browser/chromeos/preferences_chromeos_browsertest.cc
+++ b/chrome/browser/chromeos/preferences_chromeos_browsertest.cc
@@ -178,7 +178,7 @@ IN_PROC_BROWSER_TEST_F(PreferencesTest, MultiProfiles) {
 
   // Check that changing prefs of the active user doesn't affect prefs of the
   // inactive user.
-  scoped_ptr<base::DictionaryValue> prefs_backup =
+  std::unique_ptr<base::DictionaryValue> prefs_backup =
       prefs1->GetPreferenceValues();
   SetPrefs(prefs2, false);
   CheckSettingsCorrespondToPrefs(prefs2);